Antifungal activity of zinc and silver nanoparticles against dermatophyte fungi

• Grant number: 23/05260-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2023
• End date: June 30, 2025
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Regina Helena Pires
• Grantee: Maria Laura Faleiros Ribeiro de Melo
• Host Institution: Pró-Reitoria Adjunta de Pesquisa e Pós-Graduação. Universidade de Franca (UNIFRAN). Franca , SP, Brazil

Abstract

Thrichophyton rubrum and Tricophyton mentagrophytes are dermatophyte or keratinolytic fungi because they have the ability to invade, colonize and feed on keratin-rich tissues of both humans and animals and are biofilm formers, which has been hindering treatments with antifungals, even generating a rate of high reinfection. In this context, the development of new agents with different mechanisms of action is crucial, and nanoparticles (NPs) have been highlighted as a therapeutic alternative. Silver (Ag) has been used in wounds, burns and various microbial infections, and zinc oxide (ZnO) is not a heavy metal and has little toxicity to humans. Thus, the aim of this study will be to study in vitro the antifungal activity of AgNPs and ZnONPs against T. rubrum and T. mentagrophytes both in planktonic form and growth biofilm. The NPs will be chemically synthesized and characterized by ultraviolet-visible spectrophotometry (UV-Vis). The strains T. rubrum ATCC 28189 and T. mentagrophytes ATCC 11481 will be used. The antifungal activity will be obtained by the method of microdilution in broth to determine the minimum inhibitory concentration as well as the minimum inhibitory concentration of the biofilm. The anti-adhesion activity of dermatophyte biofilms will also be studied using 96-well microplates. Knowledge of the antifungal properties of nanoparticles could be used in the treatment of dermatophytoses caused by T. rubrum and T. mentagrophytes, a disease that affects a large number of people.